Structure And Electrochemical Performance Of Different Ni Doped LiMnO₂

With the mobile phone, MP4, computer and other electronic products in the proportionof our lives increasing, people’s demand is more and more. How to make more compactand sophisticated is an urgent problem to be solved. Production of high-performancelithium battery is the key solution, and good high-performance lithium battery cathodematerial of lithium batteries is a necessary component. Lithium manganese oxide cathodematerial because of its price and the advantages of resources has become a research hotspotin recent years. Besides, a mix of metals lithium manganese oxide can overcome thedisadvantage of poor stability.In this paper, we synthesized LiMnO₂compounds doped with different amount of Niby coprecipitation. The composition of the sample can be determined by ICP tests andenergy loss spectroscopy. We found that the grain size dimished with more Ni doped.Wefound that the space group of the material is R3mthrough XRD and Raman spectroscopyand with more Ni doped there is a blue shift in Raman spectroscopy. We can say that withmore Ni doped, the material contains more Mn4+through XPS analysis. But when Ni isdoped excessively, there will be Ni3+in the material. SEM analysis showed that corrosiveeffect of LiOH may have fatal effects on the electrochemical properties of the material.Recharge and discharge cycles test show that the compounds LiNi0.45Mn0.55O₂whosecharge and discharge capacity is the highest，the first circle reach298.6mAh/g. after13circles it dropped to93.2mAh/g and was steady, the efficiency reached91.3%,whichshowes good circulation performance.